A permanent magnet motor including multi-phase multi-structured stator windings is well known and has features in which torque pulsation or ripple(s) is reduced by driving the multi-phase multi-structured stator windings each at different phases, and also, a fail-safe function is enhanced due to multi-structuring the multi-phase windings. Therefore, such a permanent magnet motor is used as a motor in an electric power steering apparatus for a wheeled vehicle such as an automotive vehicle, for example.
A conventional multi-phase multi-structured permanent magnet motor disclosed in Patent Document 1 includes multi-phase stator windings made of a plurality of windings in multiple structures, and has a configuration in which each of the windings does not commonly use magnetic paths in a gap between the rotor and the stator.